Develop Reference

Unity3D: How to move an object in relation to another object?

I have a physics enabled sphere in my scene and a character that i can move around using WASD. now what i want is that as soon as player hits the ball it should not be physics enabled anymore and move along with player as like the player is holding it in the hands.
What i have tried so far:
i was able to do it but not at all perfect how i want it to be. i tried OnCollisionEnter to detect the collision, i made the sphere a child of the player, i used isKinematic = true as soon as collision is detected and i used Vector3.MoveTowards for the object to follow the position as the player.
I have attached two reference videos below
Reference Clip(The style i am aiming for):https://www.youtube.com/watch?v=fi-GB0RwLr0
MyVersion(This is what i am able to do):https://www.youtube.com/watch?v=JtV11KHY4pU
overall, if you watch the clips you can see how my version is very rigid, stucky, buggy, not so light weight feeling at all. Cut me a slack as well if i did anything way wrong, i started unity like just in the previous month.
This is my Player script through which i am controlling it all
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class Player : MonoBehaviour
{
public float MoveSpeed;
[SerializeField]private Rigidbody playerRig;
[SerializeField] private Rigidbody ballRig;
[SerializeField] private GameObject Ball;
[SerializeField] private GameObject heldObj;
private bool isTouching = false;
private Vector3 offset = new Vector3(0, 1, 3);
private Vector3 force;
public float jump;
private bool isGrounded = true;
private void Start()
{
Ball = GameObject.FindGameObjectWithTag("Ball");
ballRig.GetComponent<Rigidbody>();
playerRig.GetComponent<Rigidbody>();
}
void Update()
{
float x = Input.GetAxis("Horizontal");
float z = Input.GetAxis("Vertical");
playerRig.velocity = new Vector3(x*MoveSpeed, playerRig.velocity.y,z*MoveSpeed);
Vector3 vel = playerRig.velocity;
vel.y = 0;
if (vel.x != 0 || vel.z != 0)
{
transform.forward = vel;
}
if(transform.position.y < -10)
{
GameOver();
}
ReleaseTheBall();
if (isTouching == true)
{
ballRig.transform.position = Vector3.MoveTowards(ballRig.transform.position, playerRig.transform.position, 5f);
}
}
void Jump()
{
force = new Vector3(0, jump, 0);
if (Input.GetKeyDown(KeyCode.Space) && isGrounded == true)
{
isGrounded = false;
playerRig.AddForce(force, ForceMode.Impulse);
}
}
private void OnCollisionEnter(Collision collision)
{
if(collision.gameObject.tag == "Ball" && heldObj == null)
{
ballRig.isKinematic = true;
// ballRig.constraints = RigidbodyConstraints.FreezeRotation;
ballRig.transform.parent = playerRig.transform;
isTouching = true;
Debug.Log(" BALL PICKED UP AND MOVING ");
heldObj = Ball;
}
}
public void ReleaseTheBall()
{
if (Input.GetKeyDown(KeyCode.Space) && heldObj != null)
{
isTouching = false;
heldObj = null;
ballRig.transform.parent = null;
//ballRig.constraints = RigidbodyConstraints.None;
ballRig.isKinematic = false;
//Vector3 forceDirection = new Vector3(playerRig.transform.position.x, 0, playerRig.transform.position.z);
Vector3 rotationDirection = new Vector3(playerRig.transform.rotation.x, playerRig.transform.rotation.y, playerRig.transform.rotation.z);
ballRig.AddForce(new Vector3(transform.position.x,0,transform.position.z) * 5, ForceMode.Impulse);
ballRig.AddTorque(rotationDirection * 1);
Debug.Log("BALL RELEASED");
}
}
public void GameOver()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}
}
i know there could be some very inefficient lines of code here, feel free to call out those lines as well.
So, basically what i want is that i want my player to pick up the ball as soon as it hits it and the ball should move exactly like player as if he is holding the ball in his hands and when i hit the spacebar i want the ball to be released into the direction i am looking(this part is also very tricky for me), what i am trying to do is i want to do exactly like in the refrence clip. Thanks a lot in advance.
one more thing, when i stop pressing any key to move(WASD), my player transform keeps changing values up and down and it slightly starts moving. i mean when i dont press any key, it still kinda moves.

First of all, you have indeed quite a lot of lines that aren't useful in here and that could be optimized.
Anyway, I hope this will do what you want it to do:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
[RequireComponent(typeof(Rigidbody))]
public class Player : MonoBehaviour {
[Header("Movement Setup")]
[Tooltip("Translation speed in m/s")]
[SerializeField] float _TranslationSpeed;
[Tooltip("Rotation speed in °/s")]
[SerializeField] float _RotationSpeed;
[Tooltip("Interpolation speed [0;1]")]
[SerializeField] float _InterpolationSpeed;
[Tooltip("Strength for jumps")]
[SerializeField] float _JumpingStrength;
[Tooltip("Strength for shoots")]
[SerializeField] float _ShootingStrength;
[Header("Other Settings")]
[Tooltip("Where the helded item will be placed")]
[SerializeField] Transform _ContactPoint;
[Tooltip("Which layers should be considered as ground")]
[SerializeField] LayerMask _GroundLayer;
// The player's rigid body
Rigidbody _Rigidbody;
// Is the player on the ground
bool _IsGrounded;
// Rigidbody of what's the player is helding. Null if the player isn't holding anything
Rigidbody _HeldedItemRigidbody;
// Getter to _IsGrounded, return true if the player is grounded
public bool IsGrounded { get { return _IsGrounded; } }
private void Start() {
_Rigidbody = GetComponent<Rigidbody>(); // The player's rigidbody could be serialized
}
void FixedUpdate() {
float horizontalInput, verticalInput;
// Getting axis
horizontalInput = Input.GetAxis("Horizontal");
verticalInput = Input.GetAxis("Vertical");
// Moving toward the x
Vector3 moveVect = transform.forward * _TranslationSpeed * Time.fixedDeltaTime * verticalInput;
_Rigidbody.MovePosition(_Rigidbody.position + moveVect);
// Rotating the player based on the horizontal input
float rotAngle = horizontalInput * _RotationSpeed * Time.fixedDeltaTime;
Quaternion qRot = Quaternion.AngleAxis(rotAngle, transform.up);
Quaternion qRotUpRight = Quaternion.FromToRotation(transform.up, Vector3.up);
Quaternion qOrientationUpRightTarget = qRotUpRight * _Rigidbody.rotation;
Quaternion qNewUpRightOrientation = Quaternion.Slerp(_Rigidbody.rotation, qOrientationUpRightTarget, Time.fixedDeltaTime * _InterpolationSpeed); // We're using a slerp for a smooth movement
_Rigidbody.MoveRotation(qRot * qNewUpRightOrientation);
// This prevents the player from falling/keep moving if there is no input
if (_IsGrounded) _Rigidbody.velocity = Vector3.zero;
_Rigidbody.angularVelocity = Vector3.zero;
if (transform.position.y < -10) GameOver();
if (Input.GetKey(KeyCode.Mouse0) && _HeldedItemRigidbody != null) ShootTheBall();
if (!_IsGrounded) return; // What's below this won't be executed while jumping
if (Input.GetKey(KeyCode.Space)) Jump();
}
void Jump() {
_IsGrounded = false;
_Rigidbody.AddForce(_JumpingStrength * transform.up, ForceMode.Impulse);
}
private void OnCollisionEnter(Collision collision) {
// Checking if the player encountered a ground object
if ((_GroundLayer & (1 << collision.gameObject.layer)) > 0) _IsGrounded = true;
if (collision.gameObject.tag == "Ball") { // this can be improved as tags are error prone
// Setting the item position to contact point
collision.gameObject.transform.position = _ContactPoint.position;
// Getting the rigidbody
_HeldedItemRigidbody = collision.gameObject.GetComponent<Rigidbody>();
// Setting the parent
_HeldedItemRigidbody.transform.parent = transform;
// Setting the body to be kinematic
_HeldedItemRigidbody.isKinematic = true;
// Stopping any movement or rotation
_HeldedItemRigidbody.velocity = Vector3.zero;
_HeldedItemRigidbody.angularVelocity = Vector3.zero;
}
}
public void ShootTheBall() {
// Reverting what's done in OnCollisionEnter
_HeldedItemRigidbody.transform.parent = null;
_HeldedItemRigidbody.isKinematic = false;
// Adding force for the shoot
_HeldedItemRigidbody.AddForce(transform.forward * _ShootingStrength, ForceMode.Impulse);
// Resetting helding item to null
_HeldedItemRigidbody = null;
}
public void GameOver() {
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}
}
You have to add a layer, and set the ground to this new layer.
Set up the variable as you like, don't hesitate to mess up with it a little bit to find what suits you (and don't forget to set up the player's mass (in rigidbody) as well!!)
Exemple of setup for the player script
Last things, you have to add an empty game object to your player which will be where the ball will be placed. I know it's a little bit dirty but place it a bit far from the player (more than the ball's radius) or it will bug. We could do something programatically to fix the ball at a spot and adapt this spot to the ball's radius.
This is an example of player
As you can see, I have the empty "player" gameobject which has the rigidbody, the collider and the player script.
The GFX item which is just the capsule.
If you don't know about this: the player game object is actually on the floor (at the player's feet) so it's better for movements. If you do this, don't forget to adjust the player's capsule collider to fit the GFX.
I also have the contact point.
Forget about the nose stuff, it's just a way to see where the player is facing when you just have a capsule.
If you have any question, feel free to ask.

Unity 2D enemy movement script not flipping when moving right to left

I'm trying to write a script for my enemy movements. Here is my code:
public class EnemiesMovement : MonoBehaviour
{
private bool isFacingRight = false;
public float speed = 10f;
private float startPoint;
private float endPoint;
public float unitMovement = 2f;
private Rigidbody2D enemy;
private Animator anim;
bool moveRight;
// Start is called before the first frame update
void Start()
{
enemy = GetComponent<Rigidbody2D>();
anim = GetComponent<Animator>();
startPoint = enemy.position.x;
endPoint = startPoint + unitMovement;
}
// Update is called once per frame
void Update()
{
if (enemy.position.x >= endPoint)
moveRight = false;
if (enemy.position.x <= startPoint)
moveRight = true;
if (moveRight)
{
enemy.velocity = new Vector2(-transform.localScale.x, 0) * speed;
if (!isFacingRight)
Flip();
}
if (!moveRight)
{
enemy.velocity = new Vector2(transform.localScale.x, 0) * speed;
if (isFacingRight)
Flip();
}
}
void Flip()
{
isFacingRight = !isFacingRight;
Vector3 scale = transform.localScale;
scale.x *= -1;
transform.localScale = scale;
}
}
The movement of the enemy is right, but after the enemy flips its sprites, it doesn't change the direction of its movement. Basically, it continues to the right, even though its sprite has turned left. Can someone show me how I can fix this?
My enemy spite has a positive scale facing to the left.

Velocity is affected by the scale property.
So if you change the scale negative, everything on this GameObject flips, it's not necessary to change the velocity direction.
Are you getting bewildered? You can try another method to flip the sprite.
GetComponent<SpriteRenderer>().flipX = true;
This only flips the sprite renderer, other things are working as normal in its world space.
Another suggests as Unity documented it's better to change Rigidbody's property in the FixedUpdate.

Unity 2D rotate the AI enemy to look at player

I'm making a 2D game with two sides, left and right, so the player can only move to the left or right or jump. I made an AI as the enemy. The AI is working fine. He can go to the player to kill him.
The problem is the enemy can't rotate or face the player when he goes to kill him. I want the AI to look at the player. When the player is to the left of the enemy, the enemy should rotate to the left to look at the player. I searched many websites and I didn't get any correct solution. This is my enemy script:
public class enemy : MonoBehaviour
{
public float speed;
private Animator animvar;
private Transform target;
public GameObject effect;
public float distance;
private bool movingRight = true;
public Transform groundedDetection;
public float moveInput;
public bool facingRight = true;
void Start()
{
animvar = GetComponent<Animator>();
target = GameObject.FindGameObjectWithTag("Player").transform;
}
// Update is called once per frame
void Update()
{
if (Vector3.Distance(target.position, transform.position) < 20)
{
transform.position = Vector2.MoveTowards(transform.position, target.position, speed * Time.deltaTime);
}
else
{
transform.Translate(Vector2.right * speed * Time.deltaTime);
}
RaycastHit2D groundInfo = Physics2D.Raycast(groundedDetection.position, Vector2.down, distance);
}
void OnCollisionEnter2D(Collision2D col)
{
if (col.gameObject.tag.Equals("danger"))
{
Instantiate(effect, transform.position, Quaternion.identity);
Destroy(gameObject);
}
if (col.gameObject.tag.Equals("Player"))
{
Instantiate(effect, transform.position, Quaternion.identity);
Destroy(gameObject);
}
}
}
The game is 2D, left, right, with jump using Unity3D.

You need a function that would flip your sprite, you can do that by changing the scale of the transform, and keep a boolean to check where it's facing
bool facingRight;, so something like this
void Flip(){
Vector3 scale = transform.localScale;
scale.x *= -1;
transform.localScale = scale;
facingRight = !facingRight;
}
and in your Update check if it needs to be flipped or not
if (Vector3.Distance(target.position,transform.position)<20)
{
transform.position=Vector2.MoveTowards(transform.position, target.position,speed*Time.deltaTime);
if(target.position.x > transform.position.x && !facingRight) //if the target is to the right of enemy and the enemy is not facing right
Flip();
if(target.position.x < transform.position.x && facingRight)
Flip();
}

Its simple enough, just get the Player x position and compare to Enemy's x position, then flip the enemy sprite accordingly
This is my Update() method in my Enemy script. This handles enemy movement and changing direction the sprite is facing:
if (moveRight )
{
transform.Translate(2 * Time.deltaTime * moveSpeed, 0, 0);
transform.localScale = new Vector2(6, 6); //6,6 is just a size that suits my sprite
}
else if (!moveRight)
{
transform.Translate(-2 * Time.deltaTime * moveSpeed, 0, 0);
transform.localScale = new Vector2(-6, 6);
}
This is my enemy Attack() method , I compare the Player X position to Enemy X position. If Player X is less( to the left of the Enemy), I flip the Enemy sprite to negative
if (transform.position.x > Player.position.x)
{
transform.localScale = new Vector2(-6, 6);
}
else if (transform.position.x < Player.position.x)
{
transform.localScale = new Vector2(6, 6);
}

Missiles have a strange direction

There is a strange behavior when my spaceship fires off some missiles to destroy an enemy. Under certain circumstances, the missiles "jump" and fly away.
This seems to happen when the nearest enemy is destroyed by one missile and all others have no target any more. Then they "jump" and fly away (off the screen).
I still don't know the cause of this problem.
void Start () {
rb = this.GetComponent<Rigidbody2D>();
nearestEnemy = FindClosestTarget("EnemyShipTag");
}
Getting the closest target (enemy)
GameObject FindClosestTarget(string _target) {
enemies = GameObject.FindGameObjectsWithTag(_target);
closest = null;
distance = Mathf.Infinity;
_position = this.transform.position;
foreach (GameObject enemy in enemies) {
diff = enemy.transform.position - _position;
curDistance = diff.sqrMagnitude;
if (curDistance < distance) {
closest = enemy;
distance = curDistance;
}
}
return closest;
}
Calculate movement to nearest enemy if nearestEnemy is not null
void FixedUpdate () {
if (nearestEnemy != null) {//is enemy available?
Vector2 enemyTarget = nearestEnemy.transform.position;
Vector2 direction = (Vector2)enemyTarget - rb.position;
direction.Normalize ();
float rotateAmount = Vector3.Cross (direction, transform.up).z;
rb.angularVelocity = -rotateAmount * rotateSpeed;
float speed = 6f;
float step = speed * Time.deltaTime;
transform.position = Vector3.MoveTowards(transform.position, nearestEnemy.transform.position, step);
} else {
//rocket shall fly straight ahead if there's no target
rb.velocity = transform.up * speed;
}
These functions are part of the EnemyControl.cs-script
void OnTriggerEnter2D (Collider2D col) {//this function will trigger when there is a collision of our game objects
//detect collision of the enemy ship with the player ship, or with a player's bullet
if ((col.tag == "PlayerShipTag") || (col.tag == "MissileUpgradeTag")) {
EnemyDestroyed ();
}
void EnemyDestroyed () {
Destroy (gameObject);//Destroy the enemy ship
dead = true;
PlayerControl.enemiesDestroyed++;
}

Automatically jump script

I'm working on a 2D game (for smartphone) which is automatically jumping, and I want to give a player movement (accelerometer) (a similar principle as doodle jump). How to make automatically jumping of 2D sprite? I tried to create an animation but it will not move using the accelerometer. So I coded script for automatically jump but it's not working. any help? (automatically jump means when player hits ground, jump again)
public float speed = 6.0F;
public float jumpSpeed = 8.0F;
public float gravity = 20.0F;
private Vector3 moveDirection = Vector3.zero;
Rigidbody2D coll;
void Start(){
coll = GetComponent<Rigidbody2D>();
}
void Update() {
if (coll.gameObject.tag == "Ground") {
moveDirection = Vector3.zero;
moveDirection.x = 1;
moveDirection = transform.TransformDirection(moveDirection);
moveDirection *= speed;
}
}
}
So can someone give me script when player hit ground, player will jump? I want to move up and to the right.

Player object should have collider2D and rigidbody2D. Ground object should have collider2D and "Ground" tag. This code must be on player object.
public int power;
void Update()
{
transform.position = new Vector3(transform.position.x + Input.acceleration.x, transform.position.y, transform.position.z);
}
void OnCollisionEnter2D(Collision2D col)
{
if (col.collider.gameObject.tag.Equals("Ground"))
{
rigidbody2D.AddForce(Vector2.up * power);
}
}
I hope it works.